Staining of leather or skins



UNITED STATES PATENT OFFICE.

MARIANO PQTO, 0F PARIs, FRANCE, AssIGNoR To ANGIENS n'rnnnrssn vrmvrs A.

COMBE & FILS & CIE.,. or PARIS, FRANCE. 7

vs'ranvnve or LEATHER, 0R SKINS.

Specification of Letters Patent. Patented J 11116 29, 1 920.

No Drawing. Application filed March 25, 1916, Serial No. 86,808. Renewed October 25, 1919. Serial i e No. 333,372.

To all whom it may concern; 7

Be it known that I, 'MAnIANo Po'ro, a subject of the King of Spain, residing in Paris, France, have invented certain new and useful Improvements in'the Staining of Leather or Skins, of which the following is a specification.

The usual brown staining for leather is made by mixing anilin colors with a dressing or seasoning consisting of a solution containing albumin or blood. This staining is defective in that it is not fast to light, damp and friction. Moreover, this kind of staining can be used only for certain kinds of leather.

The present invention relates to a. process for producing a brown staining which avoids the aforesaid defects. The process comprises two distinct operations, the first consists in impregnating the skin or leather with a dyeing liquor which, owing to its composition, gives an insoluble ground, and the second consists in applying, after the leather has been glazed, (i. 6., highly polished) a topping of such composition that it imparts the desired luster to the leather.

The dyeing liquor to be used as a ground is prepared from a mixture of crystallized magenta (rosanilinhydrochlorid) and violet (penta-methylrosanilin hydrochlorid) in the proportion suitable for the tint desired. r

The dyeing liquor is prepared by dissolving 33 parts by weight of the dyestuffs in 500 parts of boiling alcohol 0f 90 per cent. strength and mixing the solution with a solution of tannin from alcohol in 450 parts of boiling alcohol of 90 per cent. strength and adding 50 parts of nitrobenzene, w ich increases the surface tension and the penetration of the color.

The topping is also made from magenta and Violet; 30 grams of the mixture of the dyestuffs are dissolved in 500 c. c. of alcohol of 90 per cent. strength, which is boiled until solution is complete. To this solution are added 35 grams of tannin from alcohol and the whole isboiled for 10 minutes.

There are then added 50 grams of bleached shellac which are dissolved by boiling the mixture gently for 15 minutes. The

whole is made up to one liter by adding.

500 c. c. of alcohol.

Thefinal polishing of the leather may be facilitated by adding to the topping or polish' 10 per cent. of its weight of amyl alcohol, but this addition is not indispensable.

The tint of the staining depend on the proportion of violet to magenta, and it can be made greener (magenta alone) or redder (violet alone).

The concentration of the polish may be varied according to the nature of'the skin and the season, the concentration "being less when evaporation is likely to be rapid.

The process may be applied to the leather as a finishing operation or to boots or shoes, both for staining them and for maintaining the color.

Having thus described my invention and the best means I know of carrying the. same into practical effect, I claim 2- A 1. Process for staining leather or skins which process consists in first impregnating the material with a dyeing liquor which gives an insoluble ground, then glazing the material and finally applying to it a top ping which imparts a luster to the material.

2. In a process for staining leather or skins the step which consists in impregnating the material with a dyeing liquor containing 33 parts by weight of a mixture of magenta and violet, in proportion to suit the desired tint, dissolved in 500 parts by weight of boiling alcohol, 20 parts by weight of tannin from alcohol dissolved in 450 parts by weight of boiling alcohol of 90 per cent. strength, and 50 parts by weight of nitrobenzene,

3. In a process for staining leather or skins the step which consists in applying upon an insoluble, ground color of magenta and violet, a topping consisting of 30 grams of a mixture of magenta and violet, in proportion to suit the desired tint, dissolved in 500 c. c. of alcohol of 90 per cent. strength, 33 grams of tannin from alcohol, 50 grams of bleached shellac and 500 c. c. of alcohol.

4. In a process for staining leather or skins the step which consists in applying upon an insoluble ground color of magenta and violet, a topping consisting of 30 grams of a mixture of magenta and violet, in proportion to suit'the desired tint, dissolved in 500 0. c. of alcohol of 90 per cent. strength, 33 grams of tannin from alcohol, 50 grams of bleached shellac, 500 c. c. of alcohol and i 10 per cent. of amyl alcohol, calculated on the weight of the whole.

5. Process for staining leather or skins which process consists in first impregnating the material with a dyeing liquor containing 33 parts by weight of a mixture of magenta and violet, in proportion to suit the desired tint, dissolved in 500 parts by weight of boiling alcohol, 20 parts by weight of tannin from alcohol dissolved in 450 parts by weight of alcohol of 90 per cent. strength and 50 parts of nitrobenzene; then glazing the material and finally applying to it a topping consisting of a mixture of magenta and violet, in proportion to suit the desired tint, dissolved in 500 c. c. of alcohol of 90 per cent; strength, 33 grams of tannin from alcohol, 50 grams of bleached shellac and 500 c. c. of alcohol. I

6. Process for staining leather or skins which process consists in first impregnating the material with a dyeing liquor containing 33 parts by weight of a mixture of magenta and violet, in proportion to suit the desired tint, dissolved in 500 parts by weightof boiling alcohol, 20 parts by weight 'of'tannin' from alcohol dissolved in 450 parts by weight of alcohol of 90 per cent. strength, and 50 parts of nitrobenzene; then glazing the material and finally applying to it a topping consisting of a mixture of magenta and violet, in proportion to suit the desired tint, dissolved in 500 c. c. of alcohol of 90 per cent.'strength, 33 grams of tannin from alcohol, 50 grams of bleached shellac, 500 c. c; of alcohol and amyl alcohol amounting to 10 per cent; by wei ht of the topping.

In Witness whereof i have hereunto signed my name in the presence of two subscribing 4Q witnesses.

MAR-IANO PQTO.

lVitnesses CHAs; P. PREss nY, HENRI CARTIER. 

